Polymeric films and display devices containing such films

ABSTRACT

Polymeric films, which may be adhesive films, and display devices including such polymeric films, wherein a polymeric film includes: a first polymeric layer having two major surfaces, wherein the first polymeric layer includes a first polymeric matrix and particles. The first polymeric layer includes: a first polymeric matrix having a refractive index n1; and particles having a refractive index n2 uniformly dispersed within the first polymeric matrix; wherein the particles are present in an amount of less than 30 vol-%, based on the volume of the first polymeric layer, and have a particle size range of 400 nanometers (nm) to 3000 nm; and wherein n1 is different than n2.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/674,530, filed Nov. 5, 2019, now pending, which is a continuation ofPCT Application No. PCT/US2018/030927, filed May 3, 2018, which is acontinuation of Ser. No. 15/587,984, issued as U.S. Pat. No. 9,960,389,the disclosure of which is incorporated by reference in their entiretyherein.

BACKGROUND

Organic light emitting diodes (OLEDs) currently are used in small-screendevices such as cell phones, personal display devices (PDAs), anddigital cameras. Current OLED markets are dominated by active-matrixorganic light-emitting diode (AMOLED) handhelds, which have atop-emissive architecture and currently do not use any light extractionmethod except for employing strong microcavity. This strong cavitydesign can have high light efficiency, but the angular color uniformityis much worse, when compared to that of liquid crystal displays (LCDs).

Typically, the color for an OLED screen shifts greatly as viewing angleincreases away from normal incidence, but an LCD display shifts onlyslightly. This is a visually evident difference between the two displaytechnologies. How to improve the angular color uniformity remains achallenge for AMOLED displays with strong cavity design.

SUMMARY OF THE DISCLOSURE

The present disclosure provides polymeric films, which may be adhesivefilms, and display devices including such polymeric films.

In one embodiment, a polymeric film includes: a first polymeric layerhaving two major surfaces, wherein the first polymeric layer includes afirst polymeric matrix and particles (preferably, polymeric particles).The polymeric film has: a clarity of at least 80%; a visible lighttransmission of at least 85%; a bulk haze of 15% to 80%; and anormalized micro-haze non-uniformity of not more than 12% across thepolymeric film. In certain embodiments, such polymeric film isvoid-free. In this context, “void-free” means that there is less than0.5 volume percent (vol-%) pores or voids.

Such a prescribed polymeric film has the optical function of a verymoderate optical diffuser with controlled local uniformity.

The first polymeric layer includes: a first polymeric matrix having arefractive index n₁; and particles having a refractive index n₂uniformly dispersed within the first polymeric matrix; wherein theparticles are present in an amount of less than 30 vol-%, based on thevolume of the first polymeric layer, and have a particle size range of400 nanometers (nm) to 3000 nm; and wherein n₁ is different than n₂.

In one embodiment, a display device includes: an organic light emittingdiode panel having a multi-layer construction that includes one or moreadhesive films; and a polymeric film as described herein incorporatedwithin the multi-layer construction of the organic light emitting diodepanel (e.g., within an adhesive film or as a replacement for an adhesivefilm); wherein the polymeric film comprises at least one adhesivematrix.

In another embodiment, a display device includes: an organic lightemitting diode panel having a multi-layer construction including one ormore adhesive films; and a polymeric film incorporated within themulti-layer construction of the organic light emitting diode panel(e.g., within an adhesive film or as a replacement for an adhesivefilm). The polymeric film includes: a first polymeric layer having twomajor surfaces, wherein the first polymeric layer comprises: a firstpolymeric matrix having a refractive index n₁; and particles having arefractive index n₂ uniformly dispersed within the first polymericmatrix; wherein the particles are present in an amount of less than 30vol-%, based on the volume of the first polymeric layer, and have aparticle size range of 400 nm to 3000 nm; and wherein n₁ is differentthan n₂.

The term “haze” refers to wide angle light scattering, wherein lightemitting from a display is diffused in all directions causing a loss ofcontrast. More particularly, the term “bulk haze” refers to the wideangle light scatter measured with a broad sampling beam of severalmillimeters (mm) so as to give an average result from saidseveral-millimeter aperture of the polymeric film. Also, moreparticularly, the term “micro-haze” refers to wide angle lightscattering as measured by a smaller illuminated area of tens of microns(i.e., less than 100 microns, e.g., 10 to 40 microns) such that theaverage micro-haze measurement represents the average result from manymeasurements, each tens of microns in area, extending over severalmillimeters of the polymeric film.

The term “normalized micro-haze non-uniformity” refers to the ratio ofthe standard deviation of the micro-haze to the average value ofmicro-haze when measured over at least 1 mm, and typically over severalmillimeters. The standard deviation of micro-haze is a measure ofmicro-haze noise. As such, normalized micro-haze non-uniformity is ametric for the ratio of visual micro-haze noise to micro-haze signal.

The term “clarity” refers to narrow angle scattering, wherein light isdiffused in a small angle range with high concentration. The effect ofhaving a certain clarity basically describes how well very small detailscan be seen through a specimen.

The terms “polymer” and “polymeric material” include, but are notlimited to, organic homopolymers, copolymers, such as for example,block, graft, random, and copolymers, terpolymers, etc., and blends andmodifications thereof. Furthermore, unless otherwise specificallylimited, the term “polymer” shall include all possible geometricalconfigurations of the material. These configurations include, but arenot limited to, isotactic, syndiotactic, and atactic symmetries.

Herein, the term “comprises” and variations thereof do not have alimiting meaning where these terms appear in the description and claims.Such terms will be understood to imply the inclusion of a stated step orelement or group of steps or elements but not the exclusion of any otherstep or element or group of steps or elements. By “consisting of” ismeant including, and limited to, whatever follows the phrase “consistingof” Thus, the phrase “consisting of” indicates that the listed elementsare required or mandatory, and that no other elements may be present. By“consisting essentially of” is meant including any elements listed afterthe phrase, and limited to other elements that do not interfere with orcontribute to the activity or action specified in the disclosure for thelisted elements. Thus, the phrase “consisting essentially of” indicatesthat the listed elements are required or mandatory, but that otherelements are optional and may or may not be present depending uponwhether or not they materially affect the activity or action of thelisted elements.

The words “preferred” and “preferably” refer to embodiments of thedisclosure that may afford certain benefits, under certaincircumstances. However, other embodiments may also be preferred, underthe same or other circumstances. Furthermore, the recitation of one ormore preferred embodiments does not imply that other embodiments are notuseful, and is not intended to exclude other embodiments from the scopeof the disclosure.

In this application, terms such as “a,” “an,” and “the” are not intendedto refer to only a singular entity, but include the general class ofwhich a specific example may be used for illustration. The terms “a,”“an,” and “the” are used interchangeably with the term “at least one.”The phrases “at least one of” and “comprises at least one of” followedby a list refers to any one of the items in the list and any combinationof two or more items in the list.

As used herein, the term “or” is generally employed in its usual senseincluding “and/or” unless the content clearly dictates otherwise.

The term “and/or” means one or all of the listed elements or acombination of any two or more of the listed elements.

Also herein, all numbers are assumed to be modified by the term “about”and in certain embodiments, preferably, by the term “exactly.” As usedherein in connection with a measured quantity, the term “about” refersto that variation in the measured quantity as would be expected by theskilled artisan making the measurement and exercising a level of carecommensurate with the objective of the measurement and the precision ofthe measuring equipment used. Herein, “up to” a number (e.g., up to 50)includes the number (e.g., 50).

Also herein, the recitations of numerical ranges by endpoints includeall numbers subsumed within that range as well as the endpoints (e.g., 1to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

As used herein, the term “room temperature” refers to a temperature of20° C. to 25° C., or in certain embodiments, 22° C. to 25° C.

The term “in the range” or “within a range” (and similar statements)includes the endpoints of the stated range.

Groupings of alternative elements or embodiments disclosed herein arenot to be construed as limitations. Each group member may be referred toand claimed individually or in any combination with other members of thegroup or other elements found therein. It is anticipated that one ormore members of a group may be included in, or deleted from, a group forreasons of convenience and/or patentability. When any such inclusion ordeletion occurs, the specification is herein deemed to contain the groupas modified thus fulfilling the written description of all Markushgroups used in the appended claims.

Reference throughout this specification to “one embodiment,” “anembodiment,” “certain embodiments,” or “some embodiments,” etc., meansthat a particular feature, configuration, composition, or characteristicdescribed in connection with the embodiment is included in at least oneembodiment of the invention. Thus, the appearances of such phrases invarious places throughout this specification are not necessarilyreferring to the same embodiment of the invention. Furthermore, theparticular features, configurations, compositions, or characteristicsmay be combined in any suitable manner in one or more embodiments.

The above summary of the present disclosure is not intended to describeeach disclosed embodiment or every implementation of the presentinvention. The description that follows more particularly exemplifiesillustrative embodiments. In several places throughout the application,guidance is provided through lists of examples, which examples may beused in various combinations. In each instance, the recited list servesonly as a representative group and should not be interpreted as anexclusive list.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional representation of a single-layer polymericfilm of the present disclosure.

FIG. 2 is a cross-sectional representation of a dual-layer polymericfilm of the present disclosure (layers are not to scale).

FIG. 3 is a cross-sectional representation of an organic light emittingdiode panel having a multi-layered construction (layers are not toscale).

FIG. 4 is a cross-sectional representation of an exemplary active-matrixorganic light-emitting diode panel (AMOLED panel).

FIG. 5 is a cross-sectional representation of a circular polarizeraccording to an exemplary embodiment of the present disclosure.

FIG. 6 is a cross-sectional representation of a capacitive touch panelaccording to an exemplary embodiment of the present disclosure.

FIG. 7 is a representation of a microscatterometry system used todetermine the micro-haze of polymeric optical films.

FIG. 8 is an optical spectrum of an exemplary film of the presentdisclosure for 3 different viewing angles.

FIG. 9 is an exemplary plot of off-angle color shift (as represented bythe corresponding shift in CIE (Commission on Illumination) colorcoordinates) versus viewing angle with and without a Wide View Color(WVC) correction polymeric film.

FIG. 10 is a plot of Samsung S4 specular reflectivity measured byLambda900 with and without a WVC correction polymeric film (essentiallyno change in ambient reflectivity).

FIG. 11 is a representation of an exemplary OLED diffuser design andoptimization process.

FIG. 12 is a plot of modeled bulk haze as a function of particle volumeloading at different particle diameter.

FIG. 13 is a plot of modeled transmission as a function of particlevolume loading at different particle diameter.

FIG. 14 is a plot of modelling results for clarity as a function ofparticle size and loading.

FIG. 15 is a plot of modeled axial brightness for an OLED device as afunction of particle size and loading for polymeric film.

FIG. 16 is a scatterplot showing correlation between simulatednormalized axial display brightness versus simulated transmission forpolymeric films of Examples 28-75.

FIG. 17 is a plot of modelling results for a maximum OLED color shiftwithin 45 degree view angle.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present disclosure provides polymeric films and display devices thatinclude these polymeric films. The polymeric film includes a polymericlayer having two major surfaces, wherein the polymeric layer includes apolymeric matrix and particles (preferably, polymeric particles).

This polymeric layer having particles is referred to as the firstpolymeric layer. The first polymeric layer includes: a first polymericmatrix having a refractive index n₁; and particles having a refractiveindex n₂ uniformly dispersed within the first polymeric matrix; whereinthe particles are present in an amount of less than 30 vol-%, based onthe volume of the first polymeric layer, and have a particle size rangeof 400 nanometers (nm) to 3000 nm; and wherein n₁ is different than n₂.Such a polymeric film has the optical function of a very moderateoptical diffuser.

In certain embodiments, the first polymeric layer is the only polymericlayer of the polymeric film of the present disclosure. In certainembodiments, the first polymeric layer is one of two polymeric layers ofthe polymeric film of the present disclosure. In certain embodiments,the first polymeric layer is one of two or more polymeric layers of thepolymeric film of the present disclosure.

As shown in FIG. 1, in certain embodiments, polymeric film 1 includes apolymeric layer 2 having two major surfaces 3 and 4, wherein thepolymeric layer 2 includes a polymeric matrix 5 and particles 6(preferably, polymeric particles) uniformly dispersed within this firstpolymeric matrix 5. In certain embodiments, such polymeric film 1 isvoid-free. In this context, “void-free” means that there is less than0.5 volume percent (vol-%) pores or voids.

As shown in FIG. 2, in certain embodiments, polymeric film 7 of thepresent disclosure includes a second polymeric layer 8 disposed on onemajor surface 3 of the first polymeric layer 2, which includes polymericmatrix 5 (i.e., first polymeric matrix 5) and particles 6. The secondpolymeric layer 8 includes a second polymeric matrix 9. The firstpolymeric matrix 5 and the second polymeric matrix 9 may be the same ordifferent.

The first polymeric matrix (the matrix in which the particles aredispersed) has a refractive index n₁, and the second polymeric matrixhas a refractive index n₃. In certain embodiments, the first polymericmatrix and the second polymeric matrix include the same material. Incertain embodiments, the first polymeric matrix is different than thesecond polymeric matrix.

In certain embodiments, if the first and second polymeric matrices aredifferent, n₁ is at least 0.05 unit different than n₃. In certainembodiments, n₁ is within 0.2 unit of n₃, and in certain embodiments, n₁is within 0.1 unit of n₃. In this context “within” means within 0.2 unit(or 0.1 unit) higher or lower.

In certain embodiments, at least one of the first polymeric matrix andthe second polymeric matrix is an adhesive matrix. In certainembodiments, the first polymeric matrix and the second polymeric matrixeach comprises an adhesive matrix. In certain embodiments, the firstadhesive matrix and the second adhesive matrix include the samematerial. In certain embodiments, the first adhesive matrix is differentthan the second adhesive matrix.

In certain embodiments, the first (possibly only) polymeric layer of thepolymeric film has a thickness of at least 10 micrometers (microns orμm). In certain embodiments, the first (possibly only) polymeric layerof the polymeric film has a thickness of up to 100 microns, or up to 50microns, or up to 25 microns, or up to 15 microns.

In certain embodiments, the second polymeric layer of the polymeric filmhas a thickness of at least 25 microns. There is no maximum thickness tothis second polymeric layer, although, in certain embodiments, it may beup to 1 millimeter (mm) thick.

In certain embodiments, the overall polymeric film has a thickness of atleast 35 microns. In certain embodiments, the overall polymeric film hasa thickness of up to 130 microns.

A polymeric film of the present disclosure has the followingcharacteristics: a clarity of at least 80% (preferably at least 85%, ormore preferably at least 90%); a visible light transmission of at least85% (preferably at least 90%); a bulk haze of 15% to 80% (preferably 20%to 80%, more preferably 30% to 70%, and even more preferably 30% to50%); and a normalized micro-haze non-uniformity of not more than 12%(preferably less than 10%, or more preferably less than 8%) across thepolymeric film.

Accordingly, such films can be used in display devices, particularlydevices that include an organic light-emitting diode display panel. Theycan function as very moderate optical diffusers with controlled localuniformity. The clarity, transmission, and bulk haze can be measuredusing a Haze Gard Plus (from BYK Gardner, Columbia, Md.), which reportsmeasurements from a sampling beam of 18 millimeters (mm) aperture of thepolymeric film, as described in the Examples Section.

The visually perceived quality of a pixelated display requires aparticular uniformity of the controlled haze for spatial distributionson the order of the length scale of the display pixels. Non-uniformityof the haze above the order of length scale of the display pixels canlead to optical defects such as pixel blur or so-called sparkle. Thisquality is measureable by means of a micro-haze uniformity measurement(Optical Property Test Method: Micro-Haze Uniformity described in theExamples Section), which provides measurements from a sampling beamilluminating a few tens of microns of the sample. In this measurement,the polymeric film surface is scanned with an optical probe that hassub-pixel dimensions while measuring standard deviation in the measuredmicro-haze levels. This micro-haze measurement technique allows sampleanalysis for spatial frequencies corresponding to the peak for humanvision perception—namely, spatial frequencies in the range of 1-5 linepairs per millimeter for typical viewing distances. The micro-hazemeasurements allow the examination of size scale variations on the sizescale for display pixel dimensions. In contrast, conventional hazemeasurement systems analyze a large area of the optical film for eachmeasurement and are unable to distinguish visually perceived differenceson the critical length scales for pixelated displays.

The polymeric films of the present disclosure can significantly improvethe known problem of color variation with viewing angle for OLEDdisplays. This problem is commonly labelled off-angle color shift, orangular color non-uniformity, and the solution to the problem describedherein is referred to as Wide View Color (WVC) correction. Thus, thepolymeric films of the present disclosure are referred to herein as WideView Color (WVC) correction films or WVC correction polymeric films.

A WVC correction polymeric film not only significantly improves angularcolor uniformity, it is compatible with a circular polarizer, maintainsbrightness and viewing angle, and does not noticeably introduce visualdefects, such as commonly known pixel blur or localized scatteringanomalies (known as “sparkle”). The pixel blur for said polymeric filmsis only slightly visible under a microscope, with negligible lightblurred into the neighboring pixels, so the visual appearance of thedisplay pixels is essentially maintained.

Significantly, the polymeric films control light diffusion andsignificantly improve angular color uniformity of OLED displays bycontrolling the differences in refractive indices between the particlesand the polymeric matrix, the size and loading of the particles, thethickness of the polymeric films, and the distance between the firstpolymeric layer of the polymeric film and display. The larger thedistance between the first polymeric layer of the polymeric film and theemissive display plane, the more undesirable pixel blur increases. Thesmaller the pixel size, the closer the first polymeric layer of thepolymeric film and display plane should be. Also, as this distanceincreases, the contrast ratio becomes undesirably low. Because of thesetwo factors, the distance between the first polymeric layer of thepolymeric film and the emissive display plane is desirably minimized.For one example, for commercially available handheld devices havingtypical pixel spacing of 50 microns, the distance between the firstpolymeric layer of the polymeric film and the emissive display planeshould preferably be less than 150 microns. For an additional example,large display monitors having typical pixel spacing of 500 microns, thedistance between the first polymeric layer of the polymeric film and theemissive display plane should preferably be less than 1500 microns. Ingeneral, the distance between the first polymeric layer of the polymericfilm and the emissive display plane is desirably less than 3 times thepixel spacing dimension of the display. Smaller first polymeric layer todisplay plane distances are even more preferable. In some embodiments,the distance between the first polymeric layer of the polymeric film andthe emissive display plane is desirably less than 2 times the pixelspacing dimension of the display. In other embodiments, the distancebetween the first polymeric layer of the polymeric film and the emissivedisplay plane is desirably less than the pixel spacing dimension for thedisplay. The polymeric films do not significantly affect majorperformance characteristics, including brightness, circular polarizercompatibility, and view angle. Also, importantly, the pixel blur can besignificantly reduced.

Particles

In the current disclosure, particles, such as polymeric particles, areuniformly dispersed within a polymeric matrix. In this context,“uniformly dispersed” means a continuous randomly dispersed particledistribution throughout a polymeric matrix. Such dispersed particles aredispersed individual particles, not aggregates or aggregations ofparticles. The presence of such aggregates creates highly localized hazedifferences that show up in a lit display as a defect known in theindustry as sparkle. Unlike typical bulk diffusers that are oftenpositioned on the backside of the display panel, such as an LCD, thecurrent application requires that the optical film be placed between thedisplay panel and the viewer, making defects due to particle aggregationmore obvious. In addition, for wide view color applications a highclarity of the optical film is often desired. Such clarity would alsomake particle agglomerates more apparent, in contrast with typicaldiffusers which are commonly higher in haze and lower in clarity.

In order to get uniformly dispersed particles in a polymer matrix,mixing processes and coating methods need to be controlled. For example,to effectively disperse particles in a polymer precursor (for example,curable monomers) or a polymer composition, mechanical mixing may becarried out for a period of time on the order of minutes. Alternatively,rolling of samples (dry particles added to polymer precursor orsolution) may be carried out, although to get complete and homogenousparticle dispersion this may have to be done for extensive periods oftime (e.g., on the order of days or weeks). Thus, roller mixing is notvery practical or effective, and mechanical mixing is preferred becauseof its efficiency and high shearing capability, which helps break up anyparticle agglomerates that may be present during the initial mixing.

In addition to mechanical mixing, controlled (slow) addition of theparticles to the components being mechanically mixed is typicallynecessary to avoid agglomeration of the individual particles. Rapidaddition of particles can easily form a “wet-cake-like solid” that isdifficult to redisperse once formed. Slow addition can involve addingsmall volumes (i.e., small shots) of particles so the mixer does not getoverwhelmed and a cake is not formed. Once a small shot of particles ismixed in, another shot is added. Once a cake forms, it can be difficultto break it up and get a completely uniform dispersion in a reasonableamount of time.

Thus, in certain embodiments, to effectively uniformly disperseparticles in a polymer matrix, a high shear mixer (e.g., disperser diskDSFB635, manufactured by Promix, Ontario, Canada) in combination withslow addition of the particles is preferred. Typically, for the morerobust polymer or inorganic beads, high shear can be used, while forsofter or more fragile particles, lower but longer shear exposure isrecommended.

Unlike the Comparative Examples 20 and 21 (see Examples Section), wherethe particles were simply dispersed in the monomer syrup and mixed on aroller for 24 hours (following one of the general procedures disclosedin International Publication No. WO 2010/033558), additional mechanicalstirring significantly reduces sparkle. In contrast to the methods usedin International Publication No. WO 2010/033558 (which typicallyinvolved dumping particles in a syrup and mixing on a roller mixer foronly a few hours because dispersion uniformity was not necessary for thedesired application, e.g., backside diffuser foran LCD), mechanicallystirring (i.e., mechanically mixing) can significantly reduce particleaggregations in solution, resulting in a uniform dispersion of particlesin a coated polymer matrix. In addition, sufficient mixing time can beused to break up particle aggregations in solution, if it occurs.Furthermore, to avoid particle settling and/or agglomeration,polymer/particle mixtures are continuously mixed, at least on a roller,until they are coated onto a substrate. In-line mixing during thecoating process can be advantageously used, provided the shear/mixingtime is sufficient to uniformly disperse the particles in the coatingcomposition. In-line mixers such as those available from Quadro(Waterloo, Ontario, Canada) may be useful.

To retain uniformly dispersed particles in the final polymeric film, itis also preferred that a coating composition is coated through aprecision coating method, such as slot die coating, where a relativelylarge gap between the die and carrier film is preferred. For Examples25-27, the addition of an optical clear adhesive layer that is notoptically functional (diffusive) opens more gap between the die andcarrier film, as a result, providing uniformly dispersed samples.Coating methods where dispersed particles may hang-up or dry on thecoating knife or die may cause issues with particle agglomeration andare generally not preferred.

The particles have a particle size range of 400 nanometers (nm) to 3000nm, or a particle size range of 700 nm to 2.0 micrometers (microns). Inthis context, “particle size” refers to the longest dimension of aparticle, which is the diameter of a spherical particle. A “particlesize range” refers to a distribution of particle sizes from the smallestto the largest (not an average). Thus, the particles are not necessarilyuniform in size. The particle size can be determined by scanningelectron microscopy (SEM).

The particles may be of a variety of shapes, including polyhedron,parallelepiped, diamond, cylinder, arcuate, arcuate cylinder, rounded(e.g., oval or spherical or equiaxial), hemisphere, gumdrop, bell, cone,frusto conical cone, irregular, and mixtures thereof. In certainembodiments, the particles are spherical beads.

The polymeric film of the present disclosure includes a first polymericlayer having two major surfaces, wherein the first polymeric layerincludes a first polymeric matrix and particles (preferably, polymericparticles) uniformly dispersed therein. The particles have a refractiveindex n₂ and the first polymeric matrix in which the particles aredispersed have a refractive index n₁, wherein n₁ is different than n₂.In certain embodiments, n₁ is at least 0.01 unit different than n₂. Incertain embodiments, n₁ is at least 0.02 unit, or at least 0.03 unit, orat least 0.04 unit, or at least 0.05 unit different than n₂. In certainembodiments, n₁ is at most 0.5 unit different than n₂, In certainembodiments, n₁ is within 0.5 unit of n₂, n₁ is within 0.4 unit of n₂,n₁ is within 0.3 unit of n₂, n₁ is within 0.2 unit of n₂, or n₁ iswithin 0.1 unit of n₂. In this context “within” means within 0.5 unit(or 0.4 unit, or 0.3 unit, or 0.2 unit, or 0.1 unit) higher or lower.

Particles are preferably organic polymeric particles, but otherparticles may be used as well. Exemplary non-organic particles includeSiO₂, Al₂O₃, ZrO₂, ZnO, and mixtures thereof. Exemplary organic polymersfor use in the organic particles include an organic polymeric materialselected from a silicone, such as a polydimethylsiloxane (PDMS), apolyurethane, a polymethyl methacrylate (PMMA), a polystyrene, or acombination thereof.

In certain embodiments, the particles are present in the first polymericlayer in an amount of less than 30 percent by volume (vol-%), based onthe volume of the first polymeric layer. In certain embodiments, theparticles are present in the first polymeric matrix in an amount of upto 25 vol-%, up to 20 vol-%, or up to 15 vol-%, based on the totalvolume of the first polymeric layer. In certain embodiments, theparticles are present in the first polymeric matrix in an amount of atleast 0.5 vol-% (or at least 1 vol-%), based on the total volume of thefirst polymeric layer.

Polymeric Matrices

A wide variety of polymers may be used in the polymeric matrices of thepolymeric films of the present disclosure. Exemplary polymers for use inthe polymeric matrices include silicones, acrylates, polyurethanes,polyesters, and polyolefins.

In certain embodiments, the polymeric matrices can be selected from asingle-phase polymer matrix or a polymer matrix having a multiphasemorphology. The multiphase morphology may be inherent in the choice ofpolymer matrix, such as for example, in a semi-crystalline polymerhaving both amorphous and crystalline domains, or may result from apolymer blend. Alternatively, the multiphase morphology may developduring drying or curing of the polymer matrix. Useful polymer matriceshaving multiphase morphology include those where each of the phases hasthe same refractive index or those where the refractive index ismismatched but the domain size of the dispersed phase does not exceedthe size of the particles dispersed in the polymer matrix.

In certain embodiments, the polymeric matrices are adhesive matrices. Incertain embodiments, at least one adhesive matrix includes an opticallyclear adhesive (OCA). In certain embodiments, the optically clearadhesive is selected from an acrylate, a polyurethane, a polyolefin(such as a polyisobutylene (PIB)), a silicone, or a combination thereof.Illustrative OCAs include those described in International Pub. No. WO2008/128073 (3M Innovative Property Co.) relating to antistaticoptically clear pressure sensitive adhesives, U.S. Pat. App. Pub. Nos.US 2009/089137 (Sherman et al.) relating to stretch releasing OCA, US2009/0087629 (Everaerts et al.) relating to indium tin oxide compatibleOCA, US 2010/0028564 (Cheng et al.) relating to antistatic opticalconstructions having optically transmissive adhesive, US 2010/0040842(Everaerts et al.) relating to adhesives compatible with corrosionsensitive layers, US 2011/0126968 (Dolezal et al.) relating to opticallyclear stretch release adhesive tape, and U.S. Pat. No. 8,557,378(Yamanaka et al.) relating to stretch release adhesive tapes. SuitableOCAs include acrylic optically clear pressure sensitive adhesives suchas, for example, 3M OCA 8146 available from 3M Company, St. Paul, Minn.

For dual layer embodiments (see, e.g., FIG. 2), the polymeric layers maybe the same material or they may be composed of two different materials.In either case, each polymeric layer may include a single-phase polymermatrix or may include a polymer matrix having a multiphase morphology.

In certain embodiments, a dual layer product construction (see, e.g.,FIG. 2) may include one layer (layer 2 in FIG. 2) having particularoptically diffusing properties and a second layer (layer 8 in FIG. 2)being an optically clear adhesive. Some of the benefits for forming adual layer product construction would be to provide improved adhesiveproperties such as peel strength, robustness, coating integrity, etc. Incases where the dual layer product is incorporated into an OLED displaydevice, the optically diffuse layer (layer 2 of the two layer system inFIG. 2) is preferably facing an OLED emissive display plane (e.g., theactive-matrix organic light-emitting diode panel 10 in FIG. 3) andplaced as close to that plane as the construction allows. For bestperformance, including contrast ratio and minimization of pixel blur,etc., the optically diffuse layer would be preferably in direct contactwith an OLED encapsulation layer(s) (e.g., a combination of a barrierfilm 14 disposed on a first adhesive film 12 in FIG. 3). If not indirect contact, the performance may be degraded as the distance betweenthe diffuse layer and emissive plane increases.

Display Devices

In certain embodiments, display devices of the present disclosureinclude: an organic light emitting diode panel having a multi-layerconstruction including one or more adhesive films; and a polymeric filmas described herein incorporated within the multi-layer construction ofthe organic light emitting diode panel. In this context, in certainembodiments, “incorporated within the multi-layer construction” meansthat the polymeric film of the present disclosure replaces one or moreadhesive films (e.g., optically clear adhesive films) of the multi-layerconstruction, particularly if the polymeric film includes an adhesivematrix. In this context, in certain embodiments, “incorporated withinthe multi-layer construction” means that the polymeric film of thepresent disclosure is incorporated into one or more adhesive films(e.g., optically clear adhesive films) of the multi-layer construction,particularly if the polymeric film itself does not include an adhesivematrix.

In certain embodiments, display devices include: an organic lightemitting diode panel having a multi-layer construction including one ormore adhesive films; and a polymeric film incorporated within themulti-layer construction of the organic light emitting diode panel. Insuch embodiments, the polymeric film includes a first polymeric layerhaving two major surfaces, wherein the first polymeric layer includes: afirst polymeric matrix having a refractive index n₁; and particleshaving a refractive index n₂ uniformly dispersed within the firstpolymeric matrix. The particles are present in an amount of less than 30vol-%, based on the volume of the first polymeric layer, and have aparticle size range of 400 nm to 3000 nm.

In such embodiments, n₁ is different than n₂. In some embodiments, n₁ isat least 0.01 unit different than n₂. In some embodiments, n₁ is atleast 0.02 unit, or at least 0.03 unit, or at least 0.04 unit, or atleast 0.05 unit different than n₂. In some embodiments, n₁ is at most0.5 unit different than n₂. In some embodiments, n₁ is within 0.5 unitof n₂, n₁ is within 0.4 unit of n₂, n₁ is within 0.3 unit of n₂, n₁ iswithin 0.2 unit of n₂, or n₁ is within 0.1 unit of n₂. In this context“within” means within 0.5 unit (or 0.4 unit, or 0.3 unit, or 0.2 unit,or 0.1 unit) higher or lower.

Significantly, in certain embodiments, a display device that includes apolymeric film of the present disclosure has an off-axis color shift(0-45°) that is at least 5% better (or at least 10% better, or at least20% better, or at least 30% better) than an off-axis color shiftcompared to a display device that includes a non-diffusive opticallyclear adhesive in place of the polymeric film. In certain embodiments, adisplay device that includes a polymeric film of the present disclosurehas an off-axis color shift (0-60°) that is at least 5% better (or atleast 10% better, or at least 20% better, or at least 30% better) thanan off-axis color shift compared to a display device that includes anon-diffusive optically clear adhesive in place of the polymeric film.In this context, a “non-diffusive” optically clear adhesive refers to anadhesive that is free of any light scattering particles or domains. Suchan adhesive typically has a bulk haze of less than 0.5%.

Display devices of the present disclosure may be flexible or rigid.Examples of OLED displays that could incorporate the polymeric films ofthe present disclosure are described in U.S. Pat. App. Nos. US2016/0001521 (Tanaka et al.), US 2014/0299844 (You et al.), and US2016/0155967 (Lee et al.).

Exemplary devices include an organic light emitting diode panel having amulti-layered construction that includes, as shown in FIG. 3, anactive-matrix organic light-emitting diode (AMOLED) panel 10; a firstadhesive film 12 disposed on the active-matrix organic light-emittingdiode panel 10; a barrier film 14 disposed on the first adhesive film12; a second adhesive film 16 disposed on the barrier film 14; acircular polarizer 18 disposed on the second adhesive film 16; a thirdadhesive film 20 disposed on the circular polarizer 18; a touch panel 22disposed on the third adhesive film 20; a fourth adhesive film 24disposed on the touch panel 22; and a cover window 26 disposed on thefourth adhesive film 24. In certain embodiments, first adhesive film 12includes an adhesive with good barrier properties like polyisobutylene.In certain embodiments, barrier film 14 is a conventionalinorganic/organic multi-layer barrier film.

The display device of FIG. 3 is exemplary only of various multi-layeredconstructions. In certain embodiments, for example, barrier film 14 isincorporated into the AMOLED panel 10. In certain embodiments, firstadhesive film 12 and barrier film 14 combined form a barrier againstmoisture and oxygen. In certain embodiments, touch panel 22 isincorporated into the AMOLED panel 10.

In certain multi-layer constructions, a polymeric film of the presentdisclosure includes at least one adhesive matrix. In such embodiments,such polymeric film can be the first adhesive film 12 (FIG. 3). Incertain multi-layer constructions, a polymeric film of the presentdisclosure does not include an adhesive matrix. In such embodiments,such polymeric film can be incorporated within the first adhesive film12 (FIG. 3).

In certain embodiments, the second, third, and/or fourth adhesive films(16, 20, 24 of FIG. 3) include (or is replaced by) a polymeric film ofthe present disclosure. In certain embodiments, the third and/or fourthadhesive films (20, 24 of FIG. 3) include (or is replaced by) apolymeric film of the present disclosure.

The adhesive films of the multi-layer construction shown in FIG. 3 thatdo not include a polymeric film include an optically clear adhesive asdescribed above. In certain embodiments, first adhesive film 12 wouldtypically have some barrier properties against moisture and oxygen.

In certain embodiments, the active-matrix organic light-emitting diodepanel (10 of FIG. 3) includes an organic electroluminescent layer. Forexample, an exemplary active-matrix organic light-emitting diode panel(AMOLED panel) is shown in FIG. 4, and includes a driving substrate 101in which a driving device array (e.g., a thin-film transistor (TFT)array) is arranged, an organic electroluminescent layer 102, a cathodeelectrode layer 103, and an encapsulation layer 104. A color filterlayer (not shown) may be further arranged between the organicelectroluminescent layer 102 and the encapsulation layer 104. Areflective layer 105 for reflecting light toward the encapsulation layer104, that is, toward a light-emitting surface 106, may be provided underthe driving substrate 101. Because the AMOLED panel is a self-emissivedisplay panel in which the organic electroluminescent layer 102generates light by using a driving signal, a separate light source(e.g., a backlight) may not be necessary.

In certain embodiments, a barrier film (14 of FIG. 3) includes anoptical substrate such as COP (cyclic olefin polymer) or PET(polyethylene terephthalate) deposited with alternating layers oforganic/inorganic materials that form an oxygen and moisture barrier.Examples of inorganic materials include silica, alumina, siliconcarbide, and silicon nitride. An example includes a cured tricyclodecanedimethanol diacrylate and silica alternating layers). The organic layersare typically highly crosslinked acrylic materials.

An exemplary circular polarizer (18 of FIG. 3) is shown in FIG. 5, whichis a cross-sectional view of the circular polarizer 200 according to anexemplary embodiment. Referring to FIG. 3, the circular polarizer 200may include a linear polarizer 202, an upper support plate 203 and alower support plate 201 that support the linear polarizer 202, and aquarter (λ/4) phase plate 204. The linear polarizer 202 may be, forexample, a polyvinyl alcohol (PVA) film. The upper support plate 203 andthe lower support plate 201 may be, for example, tri-acetyl-cellulose(TAC) films. The λ/4 phase plate 204 may be adhered to the lower supportplate 201 by using an OCA layer. Exemplary embodiments are not limitedto these types. The linear polarizer 202 linearly polarizes the externallight L1. The λ/4 phase plate 204 circularly polarizes linearlypolarized light and linearly polarizes circularly polarized light.

In certain embodiments, a touch panel (22 of FIG. 3) includes a basesubstrate configured to transmit light and a touch electrode layerconfigured to receive a touch input. For example, FIG. 6 is across-sectional view of the touch panel 300 that is a capacitive touchpanel according to an exemplary embodiment. The touch panel 300 is amanipulation unit that receives a user input. Resistive touch panels orcapacitive touch panels are used in mobile devices. Referring to FIG. 6,the touch panel 300 may include a base substrate 301 that is alight-transmitting base substrate and a touch electrode layer 305 thatis a light-transmitting touch electrode layer. The touch electrode layer305 may include first and second electrode layers 302 and 304, and adielectric layer 303 that is disposed between the first and secondelectrode layers 302 and 304.

The first electrode layer 302 may be formed by forming as a patternedthin film a conductive metal such as indium tin oxide (ITO), coppermetal mesh, or silver nanowires on the base substrate 301 by usingvacuum deposition, sputtering, or plating, etc. The dielectric layer 303may be formed on the first electrode layer 302, and the second electrodelayer 304 may be formed by forming as a patterned thin film a conductivemetal on the dielectric layer 303 by using vacuum deposition,sputtering, or plating, etc. For example, the first electrode layer 302may include a plurality of horizontal electrodes, and the secondelectrode layer 304 may include a plurality of vertical electrodes.Touch cells are formed at intersections between the horizontalelectrodes and the vertical electrodes. The horizontal electrodes maybe, for example, driving electrodes, and the vertical electrodes may be,for example, receiving electrodes. When a touching object, for example,a user's hand or a touch pen (e.g., stylus) approaches or contacts thetouch panel 300, a change in a capacitance of a touch cell occurs. Whena touch event occurs, a position of the touch cell may be detected bydetecting the change in the capacitance. Also, the touch panel 300 maybe formed so that the first and second electrode layers 302 and 304 areformed on a top surface and a bottom surface of the base substrate 301,respectively. Also, the touch panel 300 may be formed so that twosubstrates on which electrode layers are formed are bonded to eachother. The touch panel 300 may be manufactured as a pliablelight-transmitting film.

In certain embodiments, a cover window (26 of FIG. 3) includes a curvedportion and/or a flat portion. The cover window may be made of amaterial selected from glass or an optically clear plastic. The coverwindow may allow an image that is displayed on the OLED panel to be seentherethrough, and may protect the OLED panel from external shock. Thus,the cover window is made of one or more transparent materials. The coverwindow may be formed of a rigid material, e.g., glass or plastics suchas a polycarbonate or a polymethylmethacrylate. The cover window may beformed of a flexible material, e.g., plastics such as a polycarbonate ora polymethylmethacrylate.

EXEMPLARY EMBODIMENTS

Embodiment 1 is a polymeric film comprising: a first polymeric layerhaving two major surfaces, wherein the first polymeric layer comprises:a first polymeric matrix having a refractive index n₁; and particles(preferably, polymeric particles) having a refractive index n₂ uniformlydispersed within the first polymeric matrix; wherein the particles arepresent in an amount of less than 30 vol-%, based on the volume of thefirst polymeric layer, and have a particle size range of 400 nm to 3000nm; and wherein n₁ is different than n₂ (in certain embodiments, n₁ iswithin 0.5 unit of n₂, n₁ is within 0.4 unit of n₂, n₁ is within 0.3unit of n₂, n₁ is within 0.2 unit of n₂, or n₁ is within 0.1 unit ofn₂); wherein the polymeric film has: a clarity of at least 80%; avisible light transmission of at least 85%; a bulk haze of 15% to 80%(preferably 20% to 80%, more preferably 30% to 70%, and even morepreferably 30% to 50%); and a normalized micro-haze non-uniformity ofnot more than 12% across the polymeric film. In certain embodiments,such polymeric film is void-free (i.e., having less than 0.5 volumepercent (vol-%) pores or voids).

Embodiment 2 is the polymeric film of embodiment 1 further comprising asecond polymeric layer disposed on one major surface of the firstpolymeric layer; wherein the second polymeric layer comprises a secondpolymeric matrix having a refractive index n₃; wherein the firstpolymeric matrix and the second polymeric matrix are the same ordifferent; and wherein at least one of the first polymeric matrix andthe second polymeric matrix is an adhesive matrix.

Embodiment 3 is the polymeric film of embodiment 2 wherein the firstpolymeric matrix and the second polymeric matrix each comprises anadhesive matrix.

Embodiment 4 is the polymeric film of embodiment 3 wherein the firstadhesive matrix and the second adhesive matrix comprise the samematerial.

Embodiment 5 is the polymeric film of embodiment 3 wherein the firstadhesive matrix is different than the second adhesive matrix.

Embodiment 6 is the polymeric film of embodiment 2, 3, or 5 wherein n₁is different than n₃ (preferably at least 0.05 unit different) andwithin 0.2 unit of n₃.

Embodiment 7 is the polymeric film of embodiment 6 wherein n₁ is within0.1 unit of n₃.

Embodiment 8 is the polymeric film of any of embodiments 1 to 7 whereinn₁ is different than n₂ (in certain embodiments, n₁ is at least 0.01unit different than n₂, and in certain embodiments, at least 0.02 unit,or at least 0.03 unit, or at least 0.04 unit, or at least 0.05 unitdifferent) and within 0.5 unit of n₂.

Embodiment 9 is the polymeric film of embodiment 8 wherein n₁ is within0.2 unit of n₂.

Embodiment 10 is the polymeric film of any of embodiments 1 to 9 whereinthe particles have a particle size range of 700 nm to 2.0 microns.

Embodiment 11 is the polymeric film of any of embodiments 1 to 10wherein the particles are present in the first polymeric matrix in anamount of at least 0.5 vol-%, based on the total volume of the firstpolymeric layer.

Embodiment 12 is the polymeric film of any of embodiments 1 to 11wherein the particles are present in the first polymeric matrix in anamount of up to 25 vol-%, based on the total volume of the firstpolymeric layer.

Embodiment 13 is the polymeric film of embodiment 12 wherein theparticles are present in the first polymeric matrix in an amount of upto 20 vol-%, based on the total volume of the first polymeric layer.

Embodiment 14 is the polymeric film of embodiment 13 wherein theparticles are present in the first polymeric matrix in an amount of upto 15 vol-%, based on the total volume of the first polymeric layer.

Embodiment 15 is the polymeric film of any of embodiments 1 to 14wherein the first polymeric layer has a thickness of at least 10microns.

Embodiment 16 is the polymeric film of any of embodiments 1 to 15wherein the first polymeric layer has a thickness of up to 100 microns.

Embodiment 17 is the polymeric film of embodiment 16 wherein the firstpolymeric layer has a thickness of up to 25 microns.

Embodiment 18 is the polymeric film of embodiment 17 wherein the firstpolymeric layer has a thickness of up to 15 microns.

Embodiment 19 is the polymeric film of any of embodiments 2 to 18wherein the second polymeric layer has a thickness of at least 25microns.

Embodiment 20 is the polymeric film of any of embodiments 1 to 19wherein the polymeric film has a thickness of at least 35 microns.

Embodiment 21 is the polymeric film of any of embodiments 1 to 20wherein the polymeric film has a thickness of up to 130 microns.

Embodiment 22 is the polymeric film of any of embodiments 2 to 21wherein at least one adhesive matrix comprise an optically clearadhesive.

Embodiment 23 is the polymeric film of any of embodiments 1 to 22wherein the particles comprise an organic polymeric material selectedfrom a polydimethylsiloxane (PDMS), a polyurethane, a polymethylmethacrylate (PMMA), a polystyrene, or a combination thereof.

Embodiment 24 is the polymeric film of any of embodiments 2 to 23wherein the first polymeric matrix and/or the second polymeric matrixcomprise a multiphase morphology.

Embodiment 25 is a display device comprising: an organic light emittingdiode panel having a multi-layer construction comprising one or moreadhesive films; and a polymeric film of any of embodiments 1 to 24incorporated within the multi-layer construction of the organic lightemitting diode panel; wherein the polymeric film comprises at least oneadhesive matrix.

Embodiment 26 is a display device comprising: an organic light emittingdiode panel having a multi-layer construction comprising one or moreadhesive films; and a polymeric film incorporated within the multi-layerconstruction of the organic light emitting diode panel; wherein thepolymeric film comprises: a first polymeric layer having two majorsurfaces, wherein the first polymeric layer comprises: a first polymericmatrix having a refractive index n₁; and particles having a refractiveindex n₂ uniformly dispersed within the first polymeric matrix; whereinthe particles are present in an amount of less than 30 vol-%, based onthe volume of the first polymeric layer, and have a particle size rangeof 400 nm to 3000 nm; and wherein n₁ is different than n₂ (in certainembodiments, n₁ is within 0.5 unit of n₂, or n₁ is within 0.4 unit ofn₂, or n₁ is within 0.3 unit of n₂, n₁ is within 0.2 unit of n₂, or n₁is within 0.1 unit of n₂). In certain embodiments, such polymeric filmis void-free (i.e., having less than 0.5 volume percent (vol-%) pores orvoids).

Embodiment 27 is the display device of embodiment 26 further comprisinga second polymeric layer disposed on one major surface of the firstpolymeric layer; wherein the second polymeric layer comprises a secondpolymeric matrix having a refractive index n₃; wherein the firstpolymeric matrix and the second polymeric matrix are the same ordifferent; and wherein at least one of the first polymeric matrix andthe second polymeric matrix is an adhesive matrix.

Embodiment 28 is the display device of embodiment 27 wherein the firstpolymeric matrix and the second polymeric matrix each comprises anadhesive matrix.

Embodiment 29 is the display device of embodiment 28 wherein the firstadhesive matrix and the second adhesive matrix comprise the samematerial.

Embodiment 30 is the display device of embodiment 28 wherein the firstadhesive matrix is different than the second adhesive matrix.

Embodiment 31 is the display device of any of embodiments 27, 28, and 30wherein n₁ is different than n₃ (preferably at least 0.05 unitdifferent) and within 0.2 unit of n₃.

Embodiment 32 is the display device of embodiment 31 wherein n₁ iswithin 0.1 unit of n₃. Embodiment 33 is the display device of any ofembodiments 26 to 32 wherein n₁ is different than n₂ (in certainembodiments, n₁ is at least 0.01 unit different than n₂, and in certainembodiments, at least 0.02 unit, or at least 0.03 unit, or at least 0.04unit, or at least 0.05 unit different) and within 0.5 unit of n₂.

Embodiment 34 is the display device of embodiment 33 wherein n₁ iswithin 0.2 unit of n₂.

Embodiment 35 is the display device of any of embodiments 26 to 34wherein the particles have a particle size range of 700 nm to 2.0microns.

Embodiment 36 is the display device of any of embodiments 26 to 35wherein the particles are present in the first polymeric matrix in anamount of at least 0.5 vol-%, based on the total volume of the firstpolymeric layer.

Embodiment 37 is the display device of any of embodiments 26 to 36wherein the particles are present in the first polymeric matrix in anamount of up to 25 vol-%, based on the total volume of the firstpolymeric layer.

Embodiment 38 is the display device of embodiment 37 wherein theparticles are present in the first polymeric matrix in an amount of upto 20 vol-%, based on the total volume of the first polymeric layer.

Embodiment 39 is the display device of embodiment 38 wherein theparticles are present in the first polymeric matrix in an amount of upto 15 vol-%, based on the total volume of the first polymeric layer.

Embodiment 40 is the display device of any of embodiments 26 to 39wherein the first polymeric layer has a thickness of at least 10microns.

Embodiment 41 is the display device of any of embodiments 26 to 40wherein the first polymeric layer has a thickness of up to 50 microns.

Embodiment 42 is the display device of embodiment 41 wherein the firstpolymeric layer has a thickness of up to 25 microns.

Embodiment 43 is the display device of embodiment 42 wherein the firstpolymeric layer has a thickness of up to 15 microns.

Embodiment 44 is the display device of any of embodiments 26 to 43wherein the second polymeric layer has a thickness of at least 25microns.

Embodiment 45 is the display device of any of embodiments 26 to 44wherein the polymeric film has a thickness of at least 35 microns.

Embodiment 46 is the display device of any of embodiments 26 to 45wherein the polymeric film has a thickness of up to 130 microns.

Embodiment 47 is the display device of any of embodiments 27 to 46wherein the first polymeric matrix and/or the second polymeric matrixeach comprise an optically clear adhesive.

Embodiment 48 is the display device of any of embodiments 26 to 47wherein the particles comprise an organic polymeric material selectedfrom a polydimethylsiloxane (PDMS), a polyurethane, a polymethylmethacrylate (PMMA), a polystyrene, or a combination thereof.

Embodiment 49 is the display device of any of embodiments 27 to 48wherein the first polymeric matrix and/or the second polymeric matrixcomprise a multiphase morphology.

Embodiment 50 is the display device of any of embodiments 25 to 49 (thatincludes a polymeric film of the present disclosure) having an off-axiscolor shift (0-45°) that is at least 5% better (or at least 10% better,or at least 20% better, or at least 30% better) than an off-axis colorshift compared to a display device that includes a non-diffusiveoptically clear adhesive in place of the polymeric film.

Embodiment 51 is the display device of any of embodiments 25 to 50 (thatincludes a polymeric film of the present disclosure) having an off-axiscolor shift (0-60°) that is at least 5% better (in certain embodiments,at least 10% better, at least 20% better, or at least 30% better) thanan off-axis color shift compared to a display device that includes anon-diffusive optically clear adhesive in place of the polymeric film.

Embodiment 52 is the display device of any of embodiments 25 to 51 whichis flexible or rigid.

Embodiment 53 is the display device of any of embodiments 25 to 52wherein the organic light emitting diode panel comprises a multi-layeredconstruction comprising: an active-matrix organic light-emitting diodepanel; a first adhesive film disposed on the active-matrix organiclight-emitting diode panel; a barrier film disposed on the firstadhesive film; a second adhesive film disposed on the barrier film; acircular polarizer disposed on the second adhesive film; a thirdadhesive film disposed on the circular polarizer; a touch panel disposedon the third adhesive film; a fourth adhesive film disposed on the touchpanel; and a cover window disposed on the fourth adhesive film; whereinat least one of the adhesive films comprises the polymeric film.

Embodiment 54 is the display device of embodiment 53 wherein the first,second, third, and/or fourth adhesive films comprises the polymericfilm.

Embodiment 55 is the display device of embodiment 53 or 54 wherein theadhesive film that does not include the polymeric film comprises anoptically clear adhesive.

Embodiment 56 is the display device of any of embodiments 53 to 55wherein the active-matrix organic light-emitting diode panel comprisesan organic electroluminescent layer.

Embodiment 57 is the display device of any of embodiments 53 to 56wherein the barrier film comprises an optical substrate such as COP(cyclic olefin polymer) or PET (polyethylene terephthalate) depositedwith alternating layers of organic/inorganic materials that forms anoxygen and moisture barrier.

Embodiment 58 is the display device of any of embodiments 53 to 57wherein the polymeric film is compatible with the circular polarizer.

Embodiment 59 is the display device of any of embodiments 53 to 58wherein the touch panel comprises a base substrate configured totransmit light and a touch electrode layer configured to receive a touchinput.

Embodiment 60 is the display device of any of embodiments 53 to 59wherein the cover window comprises a curved portion and/or a flatportion.

Embodiment 61 is the polymeric film or display device of any ofembodiments 1 to 60 wherein the first polymeric matrix comprises anacrylate, a polyurethane, a polyolefin (such as a polyisobutylene(PIB)), a silicone, or a combination thereof.

Embodiment 62 is the polymeric film or display device of embodiment 61wherein the first polymeric matrix comprises a polyolefin.

Embodiment 63 is the polymeric film or display device of embodiment 62wherein the first polymeric matrix comprises polyisobutylene.

EXAMPLES

Objects and advantages of this invention are further illustrated by thefollowing examples, but the particular materials and amounts thereofrecited in these examples, as well as other conditions and details,should not be construed to unduly limit this invention. These examplesare merely for illustrative purposes only and are not meant to belimiting on the scope of the appended claims.

Materials

Designation Description Source PH-56 Polyester Polyol Mw = 2000, undertrade Stepan Company, Northfield, IL designation STEPANPOL PH-56 ACMAcrylamide Parchem, New Rochelle, NY HDI Hexamethylene diisocyanate,under the trade Bayer Materials Science LLC, name DESMODUR H Pittsburgh,PA MEK Methyl ethyl ketone, solvent Avantor Performance Materials, IncCenter Valley, PA DBTDA Dibutyltin diacetate Sigma-Aldrich, St. Louis,MO DMPA 2,2-Bis(hydroxymethyl)propionic acid Sigma-Aldrich, St. Louis,MO BAGM Bisphenol A-glycidyl methacrylate Sigma-Aldrich, St. Louis, MOEHA 2-Ethylhexyl acrylate BASE, Florham Park, NJ BA n-Butyl acrylateBASF, Florham Park, NJ HEA 2-Hydroxyethyl acrylate BASF, Florham Park,NJ HDDA 1,6-Hexandiol diacrylate BASF, Florham Park, NJ iBOA Isobornylacrylate Osaka chemical company, JP CN104 Epoxy acrylate oligomerSartomer, Exton, PA KBM-403 3-Glycidoxypropyl trimethoxysilane Shin-Etsusilicones of America, INC, Akron, Ohio RF02N Silicone coated polyesterrelease liner SKC Haas (Cheonan, Korea) RF12N Silicone coated polyesterrelease liner SKC Haas (Cheonan, Korea) RF22N Silicone coater polyesterrelease liner SKC Haas (Cheonan, Korea) RF52N Silicone coated polyesterrelease liner SKC Haas (Cheonan, Korea) D-11732-Hydroxy-2-methyl-1-phenyl-propan-1-one BASF, Florham Park, NJ TPO2,4,6-Trimethyl benzoyl-triphenyl oxide BASF, Florham Park, NJ IRGACUREAlpha,alpha-dimethoxy-alpha- BASF, Florham Park, NJ 651phenylacetophenone VAZO 67 2,2′-Azobis(2-methylbutyronitrile) E.I DuPont de Nemours and Company, Wilmington, Delaware IRGACURE Phosphineoxide, phenyl bis (2,4,6-trimethyl BASF, Florham Park, NJ 819 benzoyl)TOSPEARL Silicone beads (2.0 microns, monodispersed) MomentivePerformance Materials, 120A Waterford, NY TOSPEARL Silicone beads (4.5microns, monodispersed) Momentive Performance Materials, 145 Waterford,NY OPPANOL Medium molecular weight polyisobutylene BASF, Florham Park,NJ B10

Test Methods Optical Property Test Methods: Bulk Haze, Transmission,Clarity and Refractive Index

Basic optical properties including transmission, bulk haze, and clarityvalues were measured using a Haze-Guard Plus haze meter (commerciallyavailable from BYK-Gardner, Columbia, Md.). Refractive indices of thesefilms were measured using a Metricon Model 2010 Prism Coupler (availablefrom Metricon Corp., Pennington, N.J.). This instrument samples theoptical film with rather large area beam (18 millimeter (mm) diameter)to average over considerable area of display surface.

Optical Property Test Method: Micro-Haze Uniformity

Haze can be measured on a small lateral scale by focusing a probe beamonto the surface of the sample such that the focused spot is, forexample, on the order of 10 micrometers or less. This approach ofinterrogating a small area of the sample is referred to herein asmicro-haze. The micro-haze measurement technique allows sample analysisfor spatial frequencies corresponding to the peak for human visionperception and on the length scale of the display pixels. Standard hazemeasurement systems analyze a large area of the optical film and do notshow differences on the critical length scales for pixelated displays.

The microscatterometry system used to determine the micro-haze ofpolymeric optical films is shown in FIG. 7. Referring to FIG. 7,microscatterometry system 1100 included laser light source 1101(obtained from Melles Griot, Carlsbad, Calif., as Model 85-GCB-020, 532nm 20 mW DPSS laser), optical chopper (for chopping the light beam) 1111(obtained under the trade designation “NEW FOCUS 3501 OPTICAL CHOPPER”from Newport Corporation, Irvine, Calif.), light beam splitter 1113(obtained under the trade designation “UV FUSED SILICA METALLIC NEUTRALDENSITY FILTER FQR-ND01” from Newport Corporation), second lightdetector 1112 (obtained under the trade designation “NEW FOCUSLARGE-AREA PHOTORECEIVER,” Model 2031, from Newport Corporation), beamexpanding spatial filter (filtering and expanding the light beam) 1114(obtained under the trade designation “COMPACT FIVE-AXIS SPATIAL FILTERMODEL 910A” from Newport Corporation used with collimating lensachromatic doublet (1 inch diameter, 50.8 mm focal length) obtainedunder the under the trade designation “PAC040” from NewportCorporation), focusing lens 1103 (obtained under the trade designation“PAC058 ACHROMATIC DOUBLET” (1 inch diameter, 150 mm focal length fromNewport Corporation)), sample holder 1105 (a spring loaded mount(obtained under the trade designation “M-PPF50” from NewportCorporation)), sample to be tested 1130, variable aperture 1107(obtained under the trade designation “COMPACT ADJUSTABLE WIDTH SLITM-SV-0.5” from Newport Corporation), first light detector 1109 (obtainedunder the trade designation “NEW FOCUS LARGE-AREA PHOTO RECEIVER,” Model2031, from Newport Corporation) rotatable (1106) from at least −90° to90° about eucentric point 1108 in a plane parallel to the ground, and−45° to 45° about the same eucentric point 1108 in an orthogonal plane.

Other components of the microscatterometry system included a lineartranslation stage (obtained under the trade designation “MFA-1C” fromNewport Corporation), detector stages (obtained under the tradedesignation “ROTATION STAGE RV350PE” from Newport Corporation),goniometric stage (obtained under the trade designation “GONIOMETRICSTAGE BGM 160 PE” from Newport Corporation), stage drivers (for sampleand detector stages (obtained under the trade designation “UNIVERSALMOTION CONTROLLER ESP300” from Newport Corporation)), and detectionelectronics (obtained under the trade designation “ANALOG-TO-DIGITALCONVERTER NI 9215, CDAQ 9172 CHASSIS” from National Instruments, Austin,Tex.).

When light source 1101 was energized, light beam 1102 passed through andwas focused by focusing lens 1103 to a spot having a 10-micrometer spotdiameter focused at eucentric point 1108. The focused light divergedafter focal point 1104. The diverging light passed through aperture 1107before contacting first light detector 1109. Sample holder 1105translated in a plane orthogonal to the incident light beam 1102. Lightbeam splitter 1113 was used to split light beam 1102 to second lightdetector 1112. Light beam splitter 1113 transmitted about 90% of lightbeam 1102 towards focusing element 1103 and reflected about 10% of lightbeam 1102 towards second detector 1112. Second detector 1112 was used tomonitor variations in the intensity of light beam 1102 coming from lightsource 1101. The signal from first detector 1109 was divided by thesignal from second detector 1112, to account for variations in theintensity of light beam 1102.

During operation sample holder 1105 translated such that a portion ofsample holder 1105 remained at eucentric point 1108, and rotated abouteucentric point 1108.

During operation, first light detector 1109 rotated (1106) abouteucentric point 1108 and collected data generated by the scattered lightpassing through aperture 1107 onto first light detector 1109.

A probe wavelength of 532 nanometers (nm) was used to obtain theapproximately 10-micrometer focused spot diameter by using a 154-mmfocal length lens using the diameter of an Airy disc (spotdiameter=2.44×wavelength×focal length/beam diameter).

The sample was physically scanned relative to the focused spot to takemeasurements across the film surface and gather statistics formicro-haze uniformity. For each angular position of the first lightdetector with respect to the in-line direction, the light transmittedthrough the sample was measured as a function of position across thesample. The measurement at each lateral position took 1 second. In thisway, the angular spectrum of scattered light was obtained for eachlateral position of interest on the sample. The angle subtended by thefirst light detector at each angular measurement position was 0.2° inthe measurement plane and 0.85° normal to the measurement plane. Fromthese angular scatter light intensities the light intensity proportionalto the direct beam (the beam diverging from the focused spot with thesame angle as the convergence angle of the original incident beam) andthe light intensity proportional to the scattered beam are calculated.The direct beam measurement included light between 0° and 5.8° (theangle between the optic axis and the edge of the direct beam, determinedby measuring the beam with no sample in place). The scattered beammeasurement included the light projecting between 5.8° to 15.8°(representative of light scattered out of the direct beam into the first10° adjacent to the direct beam). From these two values the fractionalmicro-haze was calculated. This is defined as the ratio of scatteredbeam intensity to the sum of scattered plus transmitted direct beam.Normalizing in this way negates the effects of absorption and frontsurface reflections from the micro-haze calculation.

During the measurement, the beam was physically chopped at around 2.04kHz and both the detected signal and the source laser intensity weremeasured with a lock-in amplifier. This chopping frequency was in thelow noise and flat frequency response range of the photodetectors.Lock-in detection enabled intensity measurements over more than 4 ordersof magnitude, which is helpful when making measurements of low hazesamples, where there is a large difference in the intensities of thedirect beam and scattered beam. The micro-haze uniformity is defined asthe standard deviation of the fractional micro-haze divided by the meanfractional micro-haze measurement itself. In this way, the micro-hazeuniformity metric is functionally a noise-to-signal ratio.

OLED Color Shift Test Method

The angular color of a strong-cavity OLED device, commonly used inmobile phones, has a blue shift as the viewing angle increases. Thiseffect is commonly referred to as off-angle color shift or angular colornon-uniformity. The optical spectrum at three (3) selected viewingangles of a Samsung S5 mobile phone is illustrated in FIG. 8. Thespectrum shows three (3) spectral peaks. Although the overall spectrumdemonstrates a clear trend of shifting to shorter wavelength as theviewing angle increases, many other spectral parameters also vary—thespectral weights of the three distinct peaks change and the relativeshift of each spectral peaks are different from each other.

As a figure of merit for the off-angle color shift, it is common torepresent the color shift from the corresponding shift in CIE(Commission on Illumination) color coordinates. The CIE colorcoordinates (u,v) are measures for differing angles and the metric forcolor shift can be represented by delta_u′v′ as expressed in equation A.

delta_u′v′={[u′(θ)−u′(0)]∧2+[v′(θ)−v′(0)]∧2}∧0.5;  (A)

The sample measurement method for OLED color shift utilized a Samsung S5OLED mobile phone; the same Samsung S5 was used as the testbed for eachof the diffuse adhesive samples in the comparison. One intended use ofthe moderately diffusing polymeric film is to incorporate into the OLEDlayers, preferably directly above the OLED pixels or above the TFE layer(thin film encapsulation). For this test, however, it is consideredequivalent to measure color shifts and brightness with the polymericfilm samples placed proximate but outside of the OLED device assembly.More specifically, samples were placed immediately above the touch paneldisplay.

After mounting the samples onto the OLED device assembly, a blank whiteimage was then displayed on the OLED screen. Next, the OLED panelassembly was mounted on a rotation stage to enable angular adjustmentrelative to the measuring spectrophotometer. For this test system, aPR650 spectrophotometer (PhotoResearch Inc., Syracuse, N.Y.) was used tomeasure the color and luminance intensity of the testing assembly atevery 5 degree incremental rotation angle.

For each sample in this evaluation, the angular color shift (delta_u′v′)of the OLED device with a Wide View Color (WVC) correction polymericfilm was plotted and compared to the same OLED without a WVC correctionpolymeric film (control). An exemplary plot is shown in FIG. 9. The WVCcorrection polymeric film helps to substantially reduce the angularcolor shift of the OLED device. The maximum color shift from 0-45degrees was reduced from delta_u′v′=0.012 (control) to delta_u′v′=0.07(with polymeric film), representing a 40% reduction.

OLED Dark State Reflectivity Test Method

A mobile OLED device normally has strong specular reflection fromelectrode elements. To mitigate this problem, most assembliesincorporate a circular polarizer at the front surface to reduce ambientlight reflection. Preferably the polymeric material incorporated intothe OLED device should not depolarize and increase the ambient lightreflection. For the typical OLED display system, including a circularpolarizer element, it is desirable that the photopic reflectivity shouldnot increase by more than 5% with the incorporation of the polymericfilm for Wide View Color correction. To illustrate this, the specularreflectivity of the OLED device with circular polarizer was measuredwith and without a WVC correction polymeric film. (This particularpolymeric film is later described as Example 15.) These reflectivitymeasurements were made with Lambda900 spectrophotometer (Perkin Elmer,Waltham, Mass.) over the wavelength range of 350 nm to 800 nm. Theresulting reflectivity measurements, with and without the WVC correctionpolymeric film, are shown (FIG. 10) to have essentially no change inambient reflectivity with the addition of the diffusing polymeric film.Thus, a WVC correction film of the present disclosure is compatible witha circular polarizer. By “compatible” it is meant that no more than 5%of the light is depolarized by a WVC correction polymeric film in anOLED display system.

Optical Property Modelling Method: Bulk Haze, Transmission and Clarity

In order to understand the range of design parameters that can give riseto good device performance, optical simulation examples were compiled tomeasure and report critical “in device” metrics including Bulk Haze,Transmission, Clarity, Axial Brightness, and Angular Color Uniformity.To conduct this study, a commercially available optical software systemavailable under the tradename LIGHT TOOLS (Synopsys, Mountain View,Calif.) was utilized for the OLED polymeric film design andoptimization. The design and modelling process is illustratedschematically in FIG. 11. The experimentally measured OLED spectrum (seeFIG. 11) as input to the simulation program was the starting point. Thesimple OLED structure modeled with LIGHT TOOLS optical simulationsoftware includes a strong cavity OLED, and the diffuse polymeric layer(see FIG. 11).

The modeled examples were chosen to reflect the particular optimizationparameters for the diffusing polymeric film. These parameters includedscattering particle (e.g., bead) size, particle loading as a fraction ofvolume, refractive indices of particles and resin, and layer thickness.As the following modelling results demonstrate these parameters foroptimal WVC correction polymeric film are strongly interdependent.

Bulk haze, as a function of particle volume loading at differentparticle diameters, is illustrated in FIG. 12 representing datacollection of Examples and Comparative Examples 28-75. The correspondingdiscrete values are tabulated in Table 10. Target bulk haze levels forsuitable polymeric films is desirably 15% to 80% (preferably 20% to 80%,more preferably 30% to 70%, and even more preferably 30% to 50%) tosatisfy both pixel blur issues and provide substantive improvement incolor shift. Commensurately, the useful particle loading levels in theresin was desirably less than 30%. In this particular simulation set,the polymeric film thickness was specified to be 20 μm, refractive indexof the particles was 1.42, and the refractive index of the resin was1.49. FIG. 12 shows results for this simulation for bead diameters of200 nm, 300 nm, 400 nm, 500 nm, 1000 nm, 2000 nm, 3000 nm, and 4000 nmdiameters. From data plotted in FIG. 12, one may observe that the targetfor bulk haze greater than 50%, with a volume loading of less than 50%,requires a particle (e.g., bead) size of greater than about 300 nm. Whenthe particle size is smaller than 300 nm, the volume loading needs to beextraordinarily high and practical dispersions are difficult.

Sample transmission was also modeled as a function of particle size andvolume loading for the polymeric film. The results of transmissionversus particle volume loading are plotted in FIG. 13, which showssimulated results for particle (e.g., bead) sizes of 200 nm, 300 nm, 400nm, 500 nm, 1000 nm, 2000 nm, 3000 nm, and 4000 nm diameters. FIG. 13shows data collection from Examples and Comparative Examples 28-75. Thecorresponding discrete values are tabulated in Table 10. For a givenparticle loading, the transmission decreases significantly as theparticle size gets smaller. For example, at particle loading of 50%, thetransmission for particle sizes of 2000 nm and above remained greaterthan 85%, whereas the transmission for particle sizes of less than 400nm diameter dropped below 80%. This lower transmission of the material,in turn, reduces the OLED brightness significantly. Thus, visible lighttransmission (also referred to herein as simply “transmission”) for apolymeric film is desirably at least 85%, and preferably at least 90%.

The material clarity for the polymeric film relates to pixel blur forthe underlying display. The clarity for acceptable pixel blur isdesirably at least 80%, and preferably at least 90%. Modelling resultsfor clarity as a function of particle size and loading are shown in FIG.14 representing data collection of Examples and Comparative Examples28-75. The corresponding discrete values are tabulated in Table 10. At agiven particle loading, the material clarity decreases as the particlesize gets larger. For example, at 30% particle loading, the clarity forparticle sizes of less than 1000 nm remains above about 95%, whereas forparticle sizes of greater than 2000 nm the clarity falls below 40%.

When the polymeric film is integrated into an OLED device, the opticalperformance of the device simulations may also yield information aboutthe axial brightness metric (which correlates to transmission, haze, andclarity). The axial brightness of the OLED device as a function ofparticle size and loading is illustrated in FIG. 15 representing datacollection of Examples and Comparative Examples 28-75. The correspondingdiscrete values are tabulated in Table 10. In general, either largerparticle sizes or very small particle sizes give rise to better axialbrightness. Since the very small particle sizes have proven ineffectiveto scatter light for color uniformity, the axial brightnessconsideration shows particle sizes of greater than 500 nm arepreferable.

The axial brightness of the OLED device is affected mostly by thetransmission and haze of the polymeric film. The transmission of thefilm has the strongest influence. The larger the transmission, thebetter the axial brightness. A scattered plot of simulated OLED axialbrightness vs the transmission of the polymeric film is illustrated inFIG. 16 for polymeric films of Examples 28-75.

The primary device performance metric for this modelling exercise is theangular color shift (delta (u′,v′)). For the purpose of illustrating thedevice color shift over the same ranges of particle size (200-4000 nm)and volume loading (0-40%), the polymeric film material thickness was 20μm, the refractive index of the particles was 1.42, and the refractiveindex of the resin was 1.49 (measured at green wavelength of lambda=550nm). The maximum color shift within a 45 degree range was plotted inFIG. 17. The corresponding discrete values are tabulated in Table 10.The results show that there is no meaningful color improvement when theparticle size is too small (e.g., less than 300 nm) and also decreaseswhen the particle gets to large (e.g., greater than 3000 nm). As aresult, angular color shift indicates the preferred particle diametersare preferably in a range of 300 nm to 3 μm.

Polymer Molecular Weight Measurement Methods

The molecular weight distribution of the compounds was characterizedusing gel permeation chromatography (GPC). The GPC instrumentation,which was obtained from Waters Corporation (Milford, Mass.), included ahigh pressure liquid chromatography pump (Model 1515HPLC), anauto-sampler (Model 717), a UV detector (Model 2487), and a refractiveindex detector (Model 2410). The chromatograph was equipped with two5-micrometer PL gel MIXED-D columns available from Varian Inc. (PaloAlto, Calif.).

Samples of polymeric solutions were prepared by dissolving dried polymersamples in tetrahydrofuran at a concentration of 1.0 percent(weight/volume) and filtering through a 0.2 micrometerpolytetrafluoroethylene filter that is available from VWR International(West Chester, Pa.). The resulting samples were injected into the GPCand eluted at a rate of 1 milliliter per minute (ml/min) through thecolumns maintained at 35° C. The system was calibrated with polystyrenestandards using a linear least squares analysis to establish a standardcalibration curve. The weight average molecular weight (Mw) and thepolydispersity index (weight average molecular weight divided by numberaverage molecular weight (Mn)) were calculated for each sample againstthis standard calibration curve.

Sample Preparation Sample Preparation Methods for Polymeric FilmExamples

The diffusive polymeric film examples useful for WVC corrections werefabricated in three general product configurations or embodiments. Thefirst is in the product configuration of a single optically diffusingadhesive layer, which is represented in Examples 1-22. The second is inthe form of a non-adhesive thin volumetric diffusing element, which isrepresented in Examples 23-24. This second configuration would likely beuseful in conjunction with an additional Optically Clear Adhesive (OCA)layer to enable affixation in an integrated lamination. The thirdproduct configuration incorporates two layers in concert, at least onebeing optically diffusive, which is represented in Examples 25-27.

Modelling Examples 28-75 are included to show the projected impact ofparticle size and loading levels on clarity, bulk haze, color shift(□(u′,v′) less than 45° viewing angle), and transmission.

Examples for Product Configuration 1: Diffusing Optical Adhesive

There were three types of example fabricated for product configuration1: Single layer diffusing optical adhesive. The first set of examples(Examples 1-15) were coated out of solvent solution. The second set ofexamples (Examples 16-21) were coated from 100% solids. Lastly,Comparative Example 22 illustrates a phase separation opticallydiffusive material not incorporating particles per se.

Fabrication of Examples 1-15 (Solvent-Based)

In a glass jar, 400 grams (g) of OPPANOL B10 (PIB) and 1600 g of heptanewere added together. The glass jar was placed on a roller mixer for aweek, resulting in a homogenous 20 wt-% stock solution.

Formulations 1-4 were prepared accordingly to Table 1 below by addingdifferent levels of TOSPEARL 120A beads. A sample of 250 g of the 20wt-% t PIB stock solution as prepared above was transferred to 16-ouncejars, different levels of TOSPEARL 120A beads and additional heptanewere added to maintain 20 wt-% solids, then jars were sealed, and placedon a roller for an additional 4 days.

The Refractive Index (RI) of PIB was measured as 1.53 at 632 nm, and theRI of TOSPEARL 120A beads is 1.42 as reported by the vendor.

Formulations 1-4 were then coated on a 3-mil (75 microns) thick RF22Nliner using a 4-inch (100 mm) wide slot-type die at a line speed of 10feet per minute (ft/min) (3.3 meters per minute), and several differentflow rates to adjust the coating thickness. The tabulated values forcoating thickness are estimated or approximate thicknesses based on thematerial and pumping speed that meters the material. The coating wasdried at 200° F. (93° C.), then a 3-mil RF02N liner was laminated on thecoating to keep the material clean. Using these compositions andchanging the coating thickness yielded 15 examples.

TABLE 1 TOSPEARL OPPANOL BIO, 20 Formulation 120A Beads wt-% in HeptaneHeptane Number (grams) (grams) (grams) 1 1.28 250 5.12 2 2.63 250 10.523 5.56 250 22.24 4 8.82 250 35.28

TABLE 2 Examples for Product Construction 1 (Single-layer DiffusingAdhesive Version - Solvent-based Coating) Particle Coating Thickness,Example Formulation Loading Pump Estimated Number Number (vol-%) Speed(microns) CEx 1 1 2.50%  8 9.3 CEx 2 1 2.50%  10 11.7 Ex 3 1 2.50%  1214 Ex 4 2  5% 6 7 Ex 5 2  5% 8 9.3 Ex 6 2  5% 10 11.7 Ex 7 2  5% 12 14Ex 8 3 10% 6 7 Ex 9 3 10% 8 9.3 Ex 10 3 10% 10 11.7 Ex 11 3 10% 12 14 Ex12 4 15% 6 7 Ex 13 4 15% 8 9.3 Ex 14 4 15% 10 11.7 Ex 15 4 15% 12 14

Fabrication of Examples 16-21 (Solventless)

Formulations 5-7 were prepared for Examples 16-18 by adding differentlevels of TOSPEARL 120A beads to an adhesive solution prepared asfollows. A monomer premix was prepared by adding EHA (55 parts), iBOA(25 parts), HEA (20 parts), and 0.02 part of D-1173. The mixture waspartially polymerized under a nitrogen (inert) atmosphere by exposure toultraviolet radiation generated by an ultraviolet light emitting diode(UVA-LED) to provide a coatable syrup having a viscosity of about 1000centipoise (cps). Then HDDA (0.15 part), IRGACURE 651 (0.15 part), andKBM-403 (0.05 part) were added to the syrup to form a homogenousadhesive coating solutions.

For Formulation 5 (1 wt-% particle loading), 3 g of TOSPEARL 120A beadswere added to 297 g of adhesive solution and then mechanically stirredusing an overhead Jiffy LM Pint mixer (manufactured by Jiffy Mixer Co.Inc, Corona, Calif.) for 2 hours. After mechanical stirring, theadmixture was placed on a mixing roller for an additional 24 hours.

For Formulation 6 (1.5 wt-% particle loading), 4.5 g of TOSPEARL 120Abeads were added to 295.5 g of adhesive solution and then mechanicallystirred using an overhead Jiffy LM Pint mixer for 2 hours. Aftermechanical stirring, the admixture was placed on a mixing roller for anadditional 24 hours.

For Formulation 7 (2 wt-% particle loading), 6 g of TOSPEARL 120A beadswere added to 294 g of adhesive solution and then mechanically stirredusing an overhead Jiffy LM Pint mixer for 2 hours. After mechanicalstirring, the admixture was placed on a mixing roller for an additional24 hours.

TABLE 3 TOSPEARL Adhesive Formulation 120A Beads Solution ParticleLoading Number (grams) (grams) (wt-%) 5 3.0 297  1% 6 4.5 295.5 1.5% 7 6294 2.0%

Formulations 8 and 9 for Comparative Examples 19 and 20 were prepared byadding differing levels of TOSPEARL 145 beads to base adhesive materialprepared as follows. A monomer premix was prepared by adding EHA (50parts), iBOA (30 parts), HEA (20 parts), and 0.02 part of D-1173. Themixture was partially polymerized under a nitrogen atmosphere byexposure to ultraviolet radiation generated by UVA-LED to provide acoatable syrup having a viscosity of about 750 cps. Then HDDA (0.08part), IRGACURE 651 (0.28 part), and KBM-403 (0.05 part) were added tothe syrup to form a homogenous adhesive coating solution.

For Formulation 8, 9 g of TOSPEARL 145 beads were added to 291 g of baseadhesive material. The mixture was then transferred to a closedcontainer and placed on a mixing roller for additional 24 hours.

For Formulation 9, 11.4 g of TOSPEARL 145 beads were added to 288.6 g ofbase adhesive material. The mixture was then transferred to a closedcontainer and placed on a mixing roller for additional 24 hours.

Examples of polymeric diffusing films (Examples 16-21) were prepared byknife-coating the corresponding formulation between two silicone-treatedrelease liners at a thickness of either 25 microns or 50 microns. Theresulting coated material was then exposed to low intensity ultravioletradiation (a total energy of 1 Joule per square centimeter (J/cm²))having a spectral output from 300-400 nm with a maximum at 351 nm.

TABLE 4 TOSPEARL Adhesive Formulation 145 Beads Solution ParticleLoading Number (grams) (grams) (wt-%) 8 9.0 291  3% 9 11.4 288.6 3.8%

Phase Separation Polymer Comparative Example (CEx-22)

A bottle polymer was prepared as Formulation 10 by polymerizing acrylatemonomers in the presence of a silicone polymer (30% solid in ethylacetate), which was prepared according to Example 13 of WO 2011/082069A1modified by replacing m-xylyl-bisoxamic acid trifluoroethyl ester(Example 4 of WO 2011/082069A1) with ethylene-bis-oxamic acidtrifluoroethyl ester (Example 3 of WO 2011/082069A1). The coatingsolution was prepared in a 16-ounce jar by mixing butyl acrylate (BA),2-hydroxyethyl acrylate (HEA), the silicone polymer solution, and VAZO67 in the ratio of (BA/HEA/Silicone Polymer/VAZO 67=100/0.3/20/0.3Parts). Additional ethyl acetate was added to adjust weight percentsolids to 30 wt-%. Finally, the jar was sealed after bubbling undernitrogen for 20 min, and it was transferred to a water bath withcontrolled temp of 65° C. for 16 hours. This resulted in a hazy coatingsolution.

The solution was then coated on a RF12N liner to form a 15-micron drythick adhesive and then laminated a RF02N liner after solvent was driedout. The resulting pressure sensitive adhesive (PSA) did not have gooduniformity. An optical micrograph of the resulting PSA was taken. Fromoptical micrographs, the phase separated “particle” sizes (actually notparticles, but mixed phase spherical regions formed in situ) wereestimated to range from 2-20 microns with a volume fraction estimated asapproximately 20%.

TABLE 5 Additional Examples for Polymeric Film Composed of Single-layerDiffusing Adhesive Coating Thickness, Example Formulation Bead LoadingEstimated Number Number (wt-%) (microns) Ex 16 5 1.0% 50 Ex 17 6 1.5% 25Ex 18 7 2.0% 25 Ex 19 7 2.0% 50 CEx-20 8  3% 50 CEx-21 9 3.8% 50 CEx-2210 n.a. 15

Examples 23-24 Non-Adhesive Diffusing Element

Non-adhesive diffusing element differs from previous examples in thatthese non-adhesive polyurethane layer examples likewise illustrate themodest diffusing effect that is beneficial for WVC correction.

Synthesis of UA-Polymer (Polyurethane Acrylate Solution)

To a resin reaction vessel equipped with a mechanical stirrer, acondenser, a thermocouple, and a nitrogen inlet, the following wereadded: 81.30 g hydroxyl terminated polyester PH-56 (a hydroxyl value of57 mg KOH/g), 14.50 g DMPA, and 180.0 g of MEK. The solution was heatedup to 75° C., then with stirring the following were added: 0.48 g DBTDAand 99.16 g of HDI. The temperature was further heated up to 80±2° C.until NCO content reached was the theoretical NCO value, which wasdetermined by a standard dibutylamine back titration method. Uponobtaining the theoretical NCO value, the polyurethane was then chainextended adding a mixture of 40.0 g MEK and 40.0 g bisphenol A-glycidylmethacrylate, and allowed to react until no free NCO group was observedby FT-IR. During the reaction, 70 g of additional MEK was added into thereactor to dilute the system. Finally, the clear and transparentpolyurethane solution with 45% solids was obtained. The measured GPCdata is shown in Table 6 (Mn=number average molecular weight; Mw=weightaverage molecular weight; Mp=molar mass at peak maximum; Mz=z-averagemolecular weight; Pd=polydispersity). Units in grams/mole.

TABLE 6 Mn Mw Mp Mz Pd UA-Polymer 37731 107873 55244 271595 2.859

Formulation 11 was prepared as follows: In a 16-ounce (500-gram) brownjar, 236.8 g of UA-polymer (46 wt-% solid in MEK), 37.62 g of CN104,1.72 g of TPO, and 312 g of MEK were added. The final mixture was put ona roller for several hours to form a 25 wt-% solid coating solution. TheRI of the coating after UV-cure was measured to be 1.55.

To the above solution, 16.3 g of TOSPEARL 120 beads and 100 g of MEKwere added, and the mixture was rapidly stirred using an overhead JiffyLM Pint mixer for 2 hours. After mechanical stirring, the admixture wasplaced on a mixing roller for an additional 24 hours before it wascoated.

The coating solution was then applied on the release side of a 2-mil(50-microns) RF52N liner using a 20.3-cm (8-inch) slot-type die at aline speed of 5 ft/min (1.5 meter/min) and the adhesive flow rate wasadjusted to tune the coating thickness. The coating was dried at 200° F.(93° C.), then a 2-mil (50-microns) RF02N liner was laminated on thecoating. Finally, the coating was cured through the RF02N liner using aFusion System Model 1600 (Fusion UV Systems, Gaithersburg, Md.). TheModel 1600 was configured with an H-bulb and operated at 100% power.

TABLE 7 Examples for non-adhesive diffusing element Coating Thickness,Example Formulation Bead Loading Estimated Number Number (wt-%)(microns) Ex 23 11 10% 9 Ex 24 11 10% 15

To use the non-adhesive diffusing element to OLED devices, a standardOCA such as 3M 8146 OCA can be laminated onto the polymeric film ofExamples 23-24 to enable incorporation into a multilayer construction ofan organic light emitting diode panel of a display device.Alternatively, it is possible to overcoat the polymeric film of Examples23-24 using a solution polymer adhesives such as OPPANOL B10, B12, B15,N50, N80, N100, N150 polymers, which are commercially available fromBASF. Such adhesives can also function as moisture and oxygen barriers.

Examples for Product Configuration 3: Dual-Layer Polymeric Film(Examples 25-27)

Base Optically Clear Adhesive Formulation (Base OCA): A monomer premixwas prepared by adding EHA (55 parts), iBOA (25 parts), HEA (20 parts),and 0.02 part of D-1173. The mixture was partially polymerized under anitrogen atmosphere by exposure to ultraviolet radiation generated byUVA-LED to provide a coatable syrup having a viscosity of about 1000cps. Then HDDA (0.15 part), IRGACURE 651 (0.15 part), IRGACURE 819 (0.15part), and KBM-403 (0.05 part) were added to the syrup to form ahomogenous adhesive coating solutions.

“Diffusive” Adhesive Formulation A (DA-A): To 300 g of the BaseOptically Clear Adhesive Formulation, 19.15 g of TOSPEARL 120A beadswere added. The mixture was mechanically stirred using an overhead JiffyLM Pint mixer for 2 hours, and then it was transferred to a closedcontainer and placed on a roller for 24 hours.

“Diffusive” Adhesive Formulation B (DA-B): To 300 g of the BaseOptically Clear Adhesive Formulation, 33.33 g of TOSPEARL 120A beadswere added. The mixture was mechanically stirred using an overhead JiffyLM Pint mixer for 2 hours, and then it was transferred to a closedcontainer and placed on a roller for 24 hours.

The process for coating the dual layer product example used a dual slotfed knife coating die to deposit the coating solution onto a movingrelease liner substrate at 10 ft/min (3 meter/min). This was followed byUV pre-cure in an inert (nitrogen) atmosphere with dosage of 0.166 J/cm²UV-A from a 385-nm LED light source, as described in U.S. Pat. No.8,808,811 (Kolb et al.). Following the pre-cure, the top liner waslaminated and a final cure step used Fusion System Model I300P (H-bulb)at a dosage of 0.762 J/cm² of UV-A. The UV dose was measured using ahigh energy UV Integrating Radiometer (POWER PUCK, available from EITInc., Sterling, Va.). Coating thicknesses for each layer are controlledby the relative flow rates of the two materials to yield the thicknessesshown in Table 8.

TABLE 8 Examples for Product Construction 3 (Dual Layer) Example TopCoating Bottom Thickness (microns) Number Solution Coating Top LayerBottom Layer 25 DA-A Base OCA 16 34 26 DA-A Base OCA 12 38 27 DA-B BaseOCA 10 40

Measurement Results

TABLE 9 Measurement Results for Polymeric Film Samples of AllConstruction Types Micro-haze Color Shift Shift Thickness Bulk PropertySTD □(u′, v′) Reduction Example (μm) T (%) H (%) C (%) Mean STD Mean(<45°) □ □ □ Single layer adhesives: CEx 1 9.3 92.5 13.4 99.1 0.0097 12%CEx 2 11.7 92.4 14.7 99 0.0099 10% Ex 3 14 92.6 16.7 98.8 0.0098 11% Ex4 7 92.5 17.1 99.2 0.0095 14% Ex 5 9.3 92.3 21.1 98.4 0.0098 11% Ex 611.7 92.7 25.6 98 0.0091 17% Ex 7 14 92.5 28.9 97.3 0.0092 16% Ex 8 792.3 30.9 98.3 0.0097 12% Ex 9 9.3 92.6 36.4 96.2 0.0088 20% Ex 10 11.792.8 42.1 94.3 0.0079 28% Ex 11 14 92.7 45.9 91.5 0.0077 30% Ex 12 792.5 40.4 96.4 0.0079 28% Ex 13 9.3 92.7 46.4 91.3 0.0076 31% Ex 14 11.793 56.5 91.2 0.0078 29% Ex 15 14 92.8 62.8 91 0.0073 34% Control 25 92.20.67 99.8 0.0110 (Ex 1-15) Ex 16 50 92.1 24.2 99.1 0.0891 0.0092 10%0.008 27% Ex 17 25 92.2 26.3 99 0.0783 0.0094 12% 0.008 27% Ex 18 25 9231.5 98.7 0.0800 0.0090 11% 0.008 27% Ex 19 50 92.5 45 98.1 0.11500.0104  9% 0.007 36% CEx 20 50 45.4 0.2082 0.0257 12% NA CEx 21 50 560.2114 0.0273 13% NA CEx 22 15 90.6 48.4 81.9 0.1079 0.0203 19% 0.00827% Single Layer Non-Adhesive Ex 23 9 92.6 68.3 93.8 NA CEx 24 15 91.580.4 88.7 NA Double Layer Ex 25 50 91.5 41.5 97.3 0.0074 33% Ex 26 5091.8 32 97.8 0.0081 26% Ex 27 50 90.1 42.6 96.2 0.0067 39% Control 500.0106  4% (OCA)

TABLE 10 Modeled Examples (Single Diffusion Layer Thickness Was 20Microns) Color Shift Shift Particle Particle □(u′, Reduc- Exam- SizeLoading Bulk Property v′) tion □ ple (nm) (vol-%) T (%) H (%) C (%)(<45°) □ □ CEx 28 200 2.5 91%  2% 100% 0.0076  0% CEx 29 300 2.5 91%  4%100% 0.0076  0% CEx 30 400 2.5 92%  6% 100% 0.0074  3% CEx 31 500 2.592%  9% 100% 0.0072  5% Ex 32 1000 2.5 92% 18% 100% 0.0069  9% Ex 332000 2.5 92% 31%  98% 0.0070  8% Ex 34 3000 2.5 92% 35%  96% 0.0070  8%CEx 35 4000 2.5 92% 33%  93% 0.0070  8% CEx 36 200 5 91%  4% 100% 0.0077−1% CEx 37 300 5 91%  8% 100% 0.0077 −1% CEx 38 400 5 91% 12% 100%0.0072  5% Ex 39 500 5 91% 17% 100% 0.0067 12% Ex 40 1000 5 92% 34% 100%0.0062 18% Ex 41 2000 5 92% 51%  97% 0.0065 14% Ex 42 3000 5 92% 57% 91% 0.0065 14% CEx 43 4000 5 92% 54%  85% 0.0065 14% CEx 44 200 10 89% 8% 100% 0.0077 −1% CEx 45 300 10 89% 15% 100% 0.0077 −1% Ex 46 400 1089% 24% 100% 0.0068 11% Ex 47 500 10 90% 31% 100% 0.0060 21% Ex 48 100010 91% 56%  99% 0.0050 34% Ex 49 2000 10 92% 76%  92% 0.0054 29% CEx 503000 10 92% 80%  77% 0.0054 29% CEx 51 4000 10 92% 78%  66% 0.0054 29%CEx 52 200 20 86% 16% 100% 0.0079 −4% CEx 53 300 20 86% 29% 100% 0.0079−4% Ex 54 400 20 86% 41% 100% 0.0063 17% Ex 55 500 20 88% 52% 100%0.0049 36% Ex 56 1000 20 90% 80%  97% 0.0032 58% CEx 57 2000 20 91% 93% 74% 0.0038 50% CEx 58 3000 20 92% 94%  36% 0.0037 51% CEx 59 4000 2092% 93%  18% 0.0037 51% CEx 60 200 30 83% 23% 100% 0.0082 −8% CEx 61 30030 83% 40% 100% 0.0082 −8% CEx 62 400 30 83% 55% 100% 0.0061 20% CEx 63500 30 84% 67% 100% 0.0045 41% CEx 64 1000 30 88% 91%  95% 0.0022 71%CEx 65 2000 30 90% 97%  40% 0.0027 64% CEx 66 3000 30 91% 97%  0% 0.002567% CEx 67 4000 30 92% 97%  0% 0.0026 66% CEx 68 200 40 81% 29% 100%0.0087 −14%  CEx 69 300 40 80% 49% 100% 0.0087 −14%  CEx 70 400 40 80%66% 100% 0.0062 18% CEx 71 500 40 81% 77%  99% 0.0047 38% CEx 72 1000 4085% 96%  90% 0.0020 74% CEx 73 2000 40 89% 99%  1% 0.0022 71% CEx 743000 40 91% 98%  0% 0.0018 76% CEx 75 4000 40 91% 98%  0% 0.0020 74%Examples labelled as comparative (i.e., CEx-#) are those which result intransmission, bulk haze, and/or clarity are outside of desiredperformance range.

TABLE 11 Comparison of Subjective Visual Quality Rankings andObservations Normalized Micro-Haze Display Graininess (Samsung S5)Example Non-uniformity (%) Description Score Ex 16 10% none 0 Ex 17 12%almost none 1 Ex 18 11% very mild 2 Ex 19  9% none 0 CEx 20 12% medium 5CEx 21 13% medium 5 CEx 22 19% heavy 10 Visual Graininess (Human visualrankings from Samsung S5 comparisons)

The complete disclosures of the patents, patent documents, andpublications cited herein are incorporated by reference in theirentirety as if each were individually incorporated. Variousmodifications and alterations to this disclosure will become apparent tothose skilled in the art without departing from the scope and spirit ofthis disclosure. It should be understood that this disclosure is notintended to be unduly limited by the illustrative embodiments andexamples set forth herein and that such examples and embodiments arepresented by way of example only with the scope of the disclosureintended to be limited only by the claims set forth herein as follows.

What is claimed is:
 1. A polymeric film comprising: a first polymericlayer having two major surfaces, wherein the first polymeric layercomprises: a first polymeric matrix having a refractive index n₁; andparticles having a refractive index n₂ uniformly dispersed within thefirst polymeric matrix; wherein the particles are present in an amountof less than 30 vol-%, based on the volume of the first polymeric layer,and have a particle size range of 400 nm to 3000 nm; and wherein n₁ isdifferent than n₂; wherein the polymeric film has: a clarity of at least80%; a visible light transmission of at least 85%; and a normalizedmicro-haze non-uniformity of not more than 12% across the polymericfilm.
 2. The polymeric film of claim 1 further comprising a secondpolymeric layer disposed on one major surface of the first polymericlayer; wherein the second polymeric layer comprises a second polymericmatrix having a refractive index n₃; wherein the first polymeric matrixand the second polymeric matrix are the same or different; and whereinat least one of the first polymeric matrix and the second polymericmatrix is an adhesive matrix.
 3. The polymeric film of claim 2 whereinthe first polymeric matrix and the second polymeric matrix eachcomprises an adhesive matrix.
 4. The polymeric film of claim 2 whereinn₁ is within 0.2 unit of n₃.
 5. The polymeric film of claim 2 whereinthe second polymeric layer has a thickness of at least 25 microns. 6.The polymeric film of claim 2 wherein the first polymeric matrix and/orthe second polymeric matrix comprise a multiphase morphology.
 7. Thepolymeric film of claim 1 wherein the particles have a particle sizerange of 700 nm to 2.0 microns.
 8. The polymeric film of claim 1 whereinthe particles are present in the first polymeric matrix in an amount ofat least 0.5 vol-%, and up to 25 vol-%, based on the total volume of thefirst polymeric layer.
 9. The polymeric film of claim 1 wherein thefirst polymeric layer has a thickness of at least 7 microns and up to100 microns.
 10. The polymeric film of claim 1 wherein the particlescomprise an organic polymeric material selected from apolydimethylsiloxane (PDMS), a polyurethane, a polymethyl methacrylate(PMMA), a polystyrene, or a combination thereof.
 11. The polymeric filmof claim 1 wherein n₁ is 0.01 to 0.5 unit different than n₂.
 12. Thepolymeric film of claim 1 wherein the first polymeric matrix comprisesan acrylate, a polyurethane, a polyolefin, a silicone, or a combinationthereof.
 13. The polymeric film of claim 12 wherein the first polymericmatrix comprises a polyolefin.
 14. The polymeric film of claim 13wherein the first polymeric matrix comprises polyisobutylene.
 15. Thepolymeric film of claim 1 wherein the polymeric film has a bulk haze of15% to 96%.
 16. The polymeric film of claim 15 wherein the polymericfilm has a bulk haze of 15% to 91%.
 17. A display device comprising: anorganic light emitting diode panel having a multi-layer constructioncomprising one or more adhesive films; and a polymeric film of claim 1incorporated within the multi-layer construction of the organic lightemitting diode panel; wherein the polymeric film comprises at least oneadhesive matrix.
 18. The display device of claim 17 having an off-axiscolor shift (0-45°) that is at least 5% better than an off-axis colorshift compared to a display device that includes a non-diffusiveoptically clear adhesive in place of the polymeric film.
 19. The deviceof claim 18 having an off-axis color shift (0-60°) that is at least 5%better than an off-axis color shift compared to a display device thatincludes a non-diffusive optically clear adhesive in place of thepolymeric film.
 20. The device of claim 17 which is flexible or rigid.